23
YOUR GLOBAL CRAFTSMAN STUDIO
CUTTING
EDGE
Seamless and self-turning
It all started with a customer’s request.
They wanted to reduce the number
of insert corner changes on a mass
production machining line. They also
wanted to make complete use of the
insert’s peripheral edge. There was a
definite need for imagination in order to
meet this seemingly impossible request.
That’s when we came up with the idea
to rotate the insert itself: and invented
the rotary holder. The insert had to be
rotated, therefore in the early stages of
development we experimented with a
sliding and other types of bearings (oil
retaining, solid lubricant, carbide with
DLC coating). However, these types could
not successfully overcome the problem
of the insert rotation stopping under
certain cutting conditions. After finding
that mechanism using sliding type
bearingsmade it difficult to reliably rotate
the insert, we replaced the slide bearing
with a needle roller type. This solved the
rotation issue, but new problems arose.
There were side effects from the cutting
temperature, it was difficult to improve
lubrication and also to prevent shavings
from penetrating the bearing housing.
Downsizing was also challenge. We
cleared each problem step by step, by
using different seals and so on until the
tool could finally withstand practical use.
Whenput intoactual use, itwas found that
it was possible to use the entire periphery
of the insert, but it was also evident that
the effects of lowered relative velocity
with the workpiece also contributed to
improved wear resistance.
A rotating tool developed for themarket 20 years ago
CUTTING EDGE
Vol. 2
Tomoyoshi Sakamoto (left), Yuji Takaki (centre), Wataru Takahashi (right)
Advanced Technology Team, Development Division Processing Technology Center
Newspaper article about the development
(Nikkan Kogyo Shimbun November 12, 1996)
